Manchester United left-back Luke Shaw has a hamstring injury and is expected
to be out for around four weeks, the club have announced

Luke Shaw will miss the first month of Manchester United’s season with a hamstring problem, leaving manager Louis van Gaal facing a injury crisis for his Premier League bow.

Shaw, the £27 million summer signing, suffered the injury in training and has been ruled out for at least three weeks in what will come as a major blow to Van Gaal’s preparations ahead of Saturday’s opener against Swansea City.

With Patrice Evra and Alexander Buttner both leaving the club this summer, the loss of Shaw ensures Van Gaal does not have an experienced left-back at the club, though United are stepping up their bid to sign Sporting Lisbon’s Marcos Rojo.

United could also be without central defender Jonny Evans and winger Antonio Valencia for this weekend, after the pair both missed the pre-season friendly win over Valencia on Tuesday night.

But Shaw’s injury represents further frustration for the England international, who has already been criticised over his fitness by his new manager.

Shaw requested extra training to increase his sharpness ahead of the season yet this injury – picked up in training this week – could see him miss four league games.

Reece James, 20, played as a wing-back on the left in the Valencia game and could now make his United debut this weekend as Shaw's replacement.

Van Gaal is likely to press ahead with plans to sign Rojo, the Argentina full-back, who has handed in a transfer request at his club. United have bid around £16million for the 24-year-old who has allegedly refused to train in an attempt to push through his move to Old Trafford.

Daley Blind, Ajax’s Holland international, is another target while there is understood to be interest in Real Madrid winger Angel di Maria.

Marouane Fellaini has been offered a fresh start in Italy by Napoli manager Rafael Benitez but it appears the most likely outcome is a loan move for the Belgium midfielder.